[builtins] Introduce proper Float64Log2 and Float64Log10 operators.

src/compiler/mips/code-generator-mips.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/osr.h"
@@ skipping 735 matching lines @@
       break;
     case kIeee754Float64Atan2:
       ASSEMBLE_IEEE754_BINOP(atan2);
       break;
     case kIeee754Float64Log:
       ASSEMBLE_IEEE754_UNOP(log);
       break;
     case kIeee754Float64Log1p:
       ASSEMBLE_IEEE754_UNOP(log1p);
       break;
+    case kIeee754Float64Log2:
+      ASSEMBLE_IEEE754_UNOP(log2);
+      break;
+    case kIeee754Float64Log10:
+      ASSEMBLE_IEEE754_UNOP(log10);
+      break;
     case kMipsAdd:
       __ Addu(i.OutputRegister(), i.InputRegister(0), i.InputOperand(1));
       break;
     case kMipsAddOvf:
       // Pseudo-instruction used for overflow/branch. No opcode emitted here.
       break;
     case kMipsSub:
       __ Subu(i.OutputRegister(), i.InputRegister(0), i.InputOperand(1));
       break;
     case kMipsSubOvf:
@@ skipping 1281 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8